Japanese Patent Application publication No. H11-228013 discloses a sheet discharge apparatus in Which a plurality of discharge trays is arrayed in vertical direction and the plurality of trays is detachably attached to a support portion such as a housing. The sheet discharge apparatus performs a “discharge mode” (hereinafter simply referred to as a “stacker mode”) in which, assuming that an upper discharge tray has been removed from a support member whereas a lower discharge tray remains attached to the support member with respect to two vertically arrayed neighboring discharge trays, sheets are successively stacked on the lower discharge tray when the sheets are discharged from a sheet discharge portion in association with the detached upper discharge tray.
Therefore, larger volume of sheets can be stacked on the lower discharge tray in the stacker mode in comparison with a case where sheets are discharged from a sheet discharge portion in association with the lower discharge tray.